#include <stdio.h>
#include <time.h>
int fn(){
    int sum = 0;
    for (int i = 0; i < 30000000; i++){
        sum = 0;
        for (int j = 1; j <= 100; j++){
            sum += j;
        }
    }
    return sum;
 }
 int main(void){
    time_t start_time=0;
    time_t end_time=0;

    time(&start_time);
    fn();
    time(&end_time);
    double secode=difftime(end_time,start_time);
    printf("执行时间：%.2f秒",secode);
 }